The fact you can't get to the site throguh IE suggests something is up. So the Ip the PC has (if an NTL IP) should begin with either 62, 80, 81, 82, or 213. So if it is one of those, go into a command prompt and type ping
www.ntlworld.com and also ping 62.253.162.30 if it pings the IP and not URL then winsock2 files are borked (if this is the case I can PM you a fix for this I'll have to dig it out first). If it pings fine, then the conneciton is ok, so then it's IE.
So try the repaire in add/remove first, if it still doesn't work. Do the nets and comms. Will either need OS disk or CAB fils for this (ME has the cab files 99.9% of the time) Go into add/remove, then windows set up tab, untick communications, apply, re boot. Re tick comunications, apply, windows will copy files, re boot, try reg site through IE again.